Cabbage Tissue Research Articles

ARSENIC AND COPPER UPTAKE BY CABBAGES GROWN ON POLLUTED SOILS

Cabbages (Brassica Juncea (L.) Czern) were grown in pot experiments on typical unpolluted and polluted soils with concentration changing from 20.50 - 50.00 mg As/kg and 156.00 - 413.00 mg Cu/kg dry soil. The results demonstrate the elevation of As and Cu in soil may lead to increased uptake by these cabbages subsequent entry into human food chain. It was found 11.84- 32.12 mg As/kg and 46.86 - 94.47 mg Cu/kg dry leaves. It has tendency increase uptake and accumulation of Cu in cabbage tissue with increasing cultivated time, whereas, it was found accumulation of As in cabbages tissue decreased with time prolonging. The quantity of As and Cu in these cabbages, were significant higher than 0.2 mg As/kg and 5.0 mg Cu/kg fresh vegetable, the permissible limit concentration in fresh vegetable. This indicated that human may As and Cu exposure occur through eating these vegetables.

Characterization of high hydrostatic pressure effects on fresh produce cell turgor using pressure probe analyses

To improve the safety of fresh high quality convenience products, high hydrostatic pressure treatments (HHP) may provide a gentle, quality retainion alternative to traditional chemical preservation. However, information about the potential impact of HHP on metabolic functionality of fresh produce is rare; the few published studies indicate HHP has effects on physiological activity. These effects were highly product specific due to pronounced variations in both pressure sensitivity and stress responsivity. Biomembranes generally seem to be major physiological targets of HHP treatments. Cell turgor inevitably requires fully intact cell membranes. Turgor has an important impact on the fresh appearance of fresh produce, especially texture. Up to now, there is no investigation available that has directly evaluated the effects of HHP treatments on turgor of fresh vegetable tissue. In this study, the pressure probe technique was applied to comprehensively analyse the turgor of red cabbage tissue by directly measuring the hydrostatic pressure of individual cells. The effects of HHP on the cell turgor were tested at pressures ranging between 150MPa and 250MPa, applied for 5, 10, 15 and 20min. As pronounced changes in pressure could result in related temperature changes, the effects of temperature (35°C to 55°C) on turgor was characterised separately. At 35°C and 45°C, leaf turgor transiently declined after HHP treatment of 150MPa (for up to 10min) but recovered again within 24h; at 55°C, however, it irreversibly dropped to near zero. The same occurred when HHP of 175MPa or above was applied. In general, HHP treatment and temperature increases as well as the duration of treatments interactively affected cell turgor of red cabbage leaves. Critical process parameters derived for gentle application of HHP were 150MPa at 45°C for 10min treatment time.

Ectopic over-expression of BoHO1, a cabbage heme oxygenase gene, improved salt tolerance in Arabidopsis: A case study on proteomic analysis

Plant heme oxygenase (HO) catalyzes the oxygenation of heme to biliverdin, carbon monoxide, and free iron, and is regarded as a stress-responsive protein. Here, a cabbage HO1 gene (named as BoHO1) was isolated and characterized. BoHO1 shares a high degree homology with Arabidopsis AtHO1, and could locate in Arabidopsis chloroplast. BoHO1 mRNA was ubiquitously expressed in cabbage tissues, and was responsive to several stimuli and chemicals. Genetic evidence illustrated that over-expression of BoHO1 in transgenic Arabidopsis plants (35S:BoHO1-1 and 35S:BoHO1-2) significantly alleviated salinity stress-inhibited seedling growth, which were accompanied with the re-establishment of reactive oxygen species and ion homeostasis. Comparative proteomic analysis was subsequently performed. Results revealed that protein abundance related to light reactions was greatly suppressed by NaCl stress in wild-type, whereas was partially recovered in 35S:BoHO1-1. Salinity stress also strongly activated stress-related metabolic processes in wild-type, i.e. carbon and energy metabolism, ammonium detoxification, and protein turnover, and these induced tendencies were more intensive in 35S:BoHO1-1. Particularly, proteins related to glutathione metabolism and ion homeostasis were specifically enriched in NaCl-stressed 35S:BoHO1-1. On the basis of above results, we propose that BoHO1 could activate multiple stress-responsive pathways to help Arabidopsis regain cellular homeostasis, thus presenting enhanced adaptation to salinity stress.

Dissipation Pattern of a Fungicide Mandipropamid in Korean Cabbage at Different Harvest Times under Greenhouse Conditions

본 연구는 엇갈이배추 재배기간 중 mandelamide계 살균제인 mandipropamid를 수확 10일전 1회 살포한 후 각각 0(2시간 이내), 1, 3, 5, 7, 및 10일 후에 엇갈이배추 시료를 채취하여 mandipropamid 잔류량을 분석, 통계학적 생물학적 반감기를 산출하여 생산단계 농약잔류허용기준(Pre-Harvest Residue Limit; PHRL)을 설정하고자 하였다. Mandipropamid의 평균 회수율은 0.4 및 2.0mg·kg-1의 두 수준에서 각각 88.2 ± 3.2% 와 92.2 ± 2.0%이었으며, 분석정량한계는 0.04mg·kg-1이었다. Mandipropamid를 기준량으로 1회 살포 시 엇갈이배추 중의 생물학적 반감기는 포장 1 및 2에서 각각 3.9일과 4.0일 이었고, 생체중 증가가 mandipropamid의 잔류량 감소에 상당한 영향을 나타내었다. 잔류감소 회귀식을 이용한m andipropamid의 생산단계 잔류허용기준은 수확 10일전의 경우 11.07-12.19mg·kg-1 수준, 수확 5일전의 경우 5.76-6.05mg·kg-1 수준인 것이 바람직한 것으로 판단 되었다.

Effects of Vernalization, Temperature, and Soil Drying Periods on the Growth and Yield of Chinese Cabbage

Abstract: This study was carried out to determine the effects of vernalization, temperature, and soil water deficit (SD) on mesoph yll cells, growth, and yield of Chinese cabbage ( Brassica campestris L). The palisade parenchyma and spongy tissues of Chinese cabbage were observed under full irrigation and two weeks of SD treatment. These cells were severely collapsed by four weeks SD treatment. The SD treatment had the greatest influence on the growth of Chinese cabbage among the tested treatment factors (vernalization, temperature, and SD), growth significantly decreased by severe drought treatment (four weeks SD treatment). In addition, the relative growth rate, unit leaf rate, leaf area ratio, specific leaf area, and leaf weight ratio were si gnificantly affected by SD treatment; however, other individual factors and their combined treatments did not influence the analyzed growth parameters. The yield under vernalization after high temperature and full irrigation treatments was 3,056 kg/10 a, which was the greatest among all the tested treatments, while four-week SD treatment significantly reduced the yield. Head formation of Chinese cabbage was not altered under SD treatment, and vernalization treatments did not induce bolting. Our results indicat ed that collapsing mesophyll cells and reduced growth and yield were induced by SD treatment. Thus we suggest that optimal irrigation system should be install to avoid or overcome crippling drought conditions in the open field.Additional key words:

High Accumulation and Subcellular Distribution of Thallium in Green Cabbage (Brassica Oleracea L. Var. Capitata L.)

The accumulation of thallium (Tl) in brassicaceous crops is widely known, but both the uptake extents of Tl by the individual cultivars of green cabbage and the distribution of Tl in the tissues of green cabbage are not well understood. Five commonly available cultivars of green cabbage grown in the Tl-spiked pot-culture trials were studied for the uptake extent and subcellular distribution of Tl. The results showed that all the trial cultivars mainly concentrated Tl in the leaves (101∼192 mg/kg, DW) rather than in the roots or stems, with no significant differences among cultivars (p = 0.455). Tl accumulation in the leaves revealed obvious subcellular fractionation: cell cytosol and vacuole >> cell wall > cell organelles. The majority (∼ 88%) of leaf-Tl was found to be in the fraction of cytosol and vacuole, which also served as the major storage site for other major elements such as Ca and Mg. This specific subcellular fractionation of Tl appeared to enable green cabbage to avoid Tl damage to its vital organelles and to help green cabbage tolerate and detoxify Tl. This study demonstrated that all the five green cabbage cultivars show a good application potential in the phytoremediation of Tl-contaminated soils.

Cloning and characterization of a cabbage BoAOS gene with enhanced drought tolerance

Allene oxide synthase (AOS), which is a cytochrome P450 (CYP74A), catalyses the first step in the biosynthesis of jasmonic acid from lipoxygenase-derived hydroperoxides of free fatty acids. The full-length cDNA of an AOS-like gene was cloned from Brassica oleracea using rapid amplification of cDNA ends and was designated as BoAOS. The BoAOS expression level was higher in alabastrums and flowers than in other tissues of cabbage, as determined by real-time reverse transcription polymerase chain reaction (RT-PCR). To characterize the BoAOS gene, Arabidopsis was transformed via Agrobacterium tumefaciens with a vector to express the gene under the control of a strong constitutive promoter, CaMV35S (Cauliflower Mosaic Virus). Based on analyses of tolerance to drought stress, compared with control plants, the overexpression of BoAOS in transgenic plants increased the endogenous jasmonic acid level and conferred higher tolerance to drought stress. Therefore, we suggest that BoAOS may be a suitable candidate gene to produce transgenic plants with tolerance to drought stress.

Method for Isolating Mitochondrial DNA from Etiolated Tissue of Cabbage

Isolation of high-quality mitochondrial DNA (mtDNA) is an important premise for researching molecular mechanisms in cytoplasmic male sterility of cabbage (Brassica oleracea L.var.capitata). An efficient protocol for separation and purification of mitochondria and extraction of mitochondrial DNA (mtDNA) from etiolated tissues of cabbage was developed. We took a method combined mannitol density gradient with differential centrifugation, selected appropriate rotational speed, extended DNase I treating time and changed mitochondria cracking condition. The results showed that the extracted mitochondria in this protocol had complete structure, appeared to ellipsoid and had not been contaminated with other impurities under the Jannus Green B staining. The isolated mitochondrial DNA had high purity and yield through detecting the optical density, nuclear specific primer PCR and agarose gel electrophoresis. The results indicated that mitochondrial DNA extracted by this protocol had high quality and enabled to be used in futher genetic studies.

Effects of Cabbage Tissue and Calcium Hypochlorite on Soil Fertility and Yields of Selected Solanaceous Crops

The objective of this study was to determine the effect of inorganic compounds treatment(s) namely: Chalim (CM), a chlorine-containing compound, metham sodium (MS) (positive control) and Co (negative control) versus organic compound such as Brassica tissue treatment (BT), on soil pH, micro and macroelements. Three levels of Chalim and that of Brassica tissue; one of MS and one for Co were used. The test crops included were; Tomato, capsicum and potato. All the plots were inoculated with R. solanacearum to a level of approximately 7.5×10 Colony forming unit (CFU) per plot. Soil samples were taken using zigzag method after which the selected parameter levels were determined at the beginning and at the end of each season for three seasons (2009-2010). The amendments were prepared and applied in the field plots measuring (4.5×2.7 M) in randomized complete block design at Kenya agricultural research institute National agricultural laboratories in plant pathology section and Department of Plant and Microbial Sciences, Kenyatta university. The effects of the soil amendments on soil physico-chemical properties and yields were determined. The findings established that, Brassica tissue, at highest level of Review Article Annual Research & Review in Biology, 4(3): 547-559, 2014 548 application was the best soil amendment to be incorporated since more nutrients and yields were realized at that treatment as compared to the others. The various treatments differed significantly on their effect on the total yields. In tomato, the various treatments differed significantly (P<0.05) with plants grown on MS200 and BT5292 having significantly higher yields than the control. The study revealed that BT5292 increased the soil pH, yields, Nitrogen content, organic carbon, calcium and potassium concentration as compared to the other treatments and the control.

Vegetable surface sterilization system using UVA light-emitting diodes.

Surface sterilization of fresh produce has been needed in the food manufacturing/processing industry. Here we report a UVA-LED (Ultra Violet A-Light Emitting Diode) system for surface sterilization that is safe, efficacious, low cost, and apparently harmless to fresh produce. To test the system, Escherichia coli strain DH5α was spot-inoculated onto vegetable tissues, and treated under UVA-LED. Tissues were homogenized and bacteria quantified by colony-forming assay. Possible effects of UVA-LED on vegetable quality were evaluated by HPLC. Tissue weight changes were checked after treatment at 4℃, 15℃, and 30℃. Bacterial inactivation by UVA-LED radiation was observed after a 10 min treatment and increased with increasing time of irradiation. The log survival ratio reached -3.23 after a 90 min treatment. Bacterial cells surviving treatment grew slowly compared to non-irradiated control cells. Cabbage tissue lost weight over time after treatment, and weight loss increased with increasing incubation temperature, but there was no difference between losses by UVA-LED treated and control tissues at any temperature tested. In addition, no differences of Vitamin C content in cabbage tissue were detected by HPLC after UVA-LED treatment. These results suggest that UVA-LED treatment has great potential for vegetable surface sterilization in the food manufacturing/processing industry.

Traumatin- and Dinortraumatin-containing Galactolipids in Arabidopsis: THEIR FORMATION IN TISSUE-DISRUPTED LEAVES AS COUNTERPARTS OF GREEN LEAF VOLATILES

Green leaf volatiles (GLVs) consisting of six-carbon aldehydes, alcohols, and their esters, are biosynthesized through the action of fatty acid hydroperoxide lyase (HPL), which uses fatty acid hydroperoxides as substrates. GLVs form immediately after disruption of plant leaf tissues by herbivore attacks and mechanical wounding and play a role in defense against attackers that attempt to invade through the wounds. The fates and the physiological significance of the counterparts of the HPL reaction, the 12/10-carbon oxoacids that are formed from 18/16-carbon fatty acid 13-/11-hydroperoxides, respectively, are largely unknown. In this study, we detected monogalactosyl diacylglycerols (MGDGs) containing the 12/10-carbon HPL products in disrupted leaf tissues of Arabidopsis, cabbage, tobacco, tomato, and common bean. They were identified as an MGDG containing 12-oxo-9-hydroxy-(E)-10-dodecenoic acid and 10-oxo-7-hydroxy-(E)-8-decenoic acid and an MGDG containing two 12-oxo-9-hydroxy-(E)-10-dodecenoic acids as their acyl groups. Analyses of Arabidopsis mutants lacking HPL indicated that these MGDGs were formed enzymatically through an active HPL reaction. Thus, our results suggested that in disrupted leaf tissues, MGDG-hydroperoxides were cleaved by HPL to form volatile six-carbon aldehydes and non-volatile 12/10-carbon aldehyde-containing galactolipids. Based on these results, we propose a novel oxylipin pathway that does not require the lipase reaction to form GLVs.

Thallium at the interface of soil and green cabbage (Brassica oleracea L. var. capitata L.): Soil–plant transfer and influencing factors

Thallium (Tl) is a non-essential and toxic trace metal found in many plants, but it can accumulate at particularly high concentration in green cabbage (Brassica oleracea L. var. capitata L.). The aim of this study is to explore the transfer and accumulation of Tl at the interface of rhizospheric soil and green cabbage from a long-term Tl contaminated site in southwestern Guizhou Province, China. Influencing factors such as Tl distribution in various soil fractions and physical–chemical characteristics of rhizospheric soil were also investigated. Our results demonstrated that green cabbage had high accumulation of Tl, with most bioconcentration factor (BF) values exceeding 1, and up to a maximum level of 11. The enrichment of Tl in the green cabbage tissues followed a descending order, i.e. old leaves>fresh leaves>stems≈roots. The stems functioned as a channel for Tl transportation to the leaves, where most of the Tl (greater than 80%) was found to accumulate. In the rhizospheric soils, 62–95% of Tl existed in the residual fraction, while lower concentrations of Tl (on average, 1.7% of total T1 in rhizospheric soil) were found in the water and acid soluble fractions. The major fraction of labile Tl was located in the reducible fraction (9%). Our results also suggested that the uptake and enrichment of Tl in green cabbage were affected by Tl concentrations, soil water content, soil pH, soil organic material (SOM) and cation exchange capacity (CEC) in rhizospheric soil.

Flavobacterium hercynium EPB-C313 균주를 이용한 배추 뿌리혹병 생물적 방제

Plasmodiophora brassicae에 의한 배추 뿌리혹병은 배추뿐만 아니라 순무, 양배추에 발병하여 큰 피해를 주는 병원균이다. 배추 뿌리혹병균에 길항효과가 있는 미생물을 선발하기 위하여 배추 조직에서 분리한 Flavobacterium hercynium EPB-C313 균주의 항균활성 검정을 하였고, 포장시험을 통하여 배추 뿌리혹병에 대한 방제효과를 조사하였다. F. hercynium EPB-C313의 균체, 배양액, 배양여액를 배추 뿌리혹병 휴면포자와 혼합 처리하여 24시간 후 조사하였을 때 각각 90.4%, 36.8% 및 26.0%의 휴면포자가 불활성화 되었다. 온실 포트검정에서는 배추의 어린묘를 F. hercynium EPB-C313 배양액에 침지한 후 정식하면 뿌리혹 형성 억제율이 100%로 대조약제 fluazinam액상수 화제의 91.7%보다 우수한 효과를 나타내었다. 배추 뿌리혹병이 50% 이상 발병되었던 재배포장에 F. hercynium EPB-C313 혼합펠렛을 토양혼화 하고, F. hercynium EPBC313 배양액의 유묘관주 및 정식 10일 후 1회 토양관주하면 63.7%의 방제효과를 보였다. 이상의 결과로 볼 때 F. hercynium EPB-C313 균주는 매우 유용한 배추 뿌리혹병 생물적 방제제로 판단된다. Clubroot of Chinese cabbage by Plasmodiophora brassicae, was found to be high virulent to the Chinese cabbage, turnips and cabbage. It this study, the endophytic bacteria Flavobacterium hercynium EPB-C313, which was isolated from tissues of Chinese cabbage, was investigated the antimicrobial activity on the inactivation of resting spores and its control effect on clubroot disease by bioassay. The bacterial cells, culture solutions, and culture filtrates of F. hercynium EPB-C313 inactivate the resting spores of P. brassicae with 90.4, 36.8, and 26.0%, respectively. The clubroot was inhibited with 100% by dipping the seedlings of Chinese cabbage in culture solutions of F. hercynium EPB-C313 before planting, however the chemmical 'fluazinam' was 91.7% in pot tests. Complex treatment were highly enhanced control efficacy with 63.7% at field of 50% diseased plants by soil incorporation with the pellet contains organic matter and F. hercynium EPB-C313, seedling drench of culture solution of F. hercynium EPB-C313 and soil drench with 10 days after planting. These results imply that the F. hercynium EPB-C313 is a very useful biological control agent of clubroot disease of Chinese cabbage.

Uranium in vegetable foodstuffs: should residents near the Cunha Baixa uranium mine site (Central Northern Portugal) be concerned?

Large uranium accumulations in vegetable foodstuffs may present risks of human health if they are consumed. The objective of this study was to evaluate the uranium concentrations in different vegetable foodstuffs and grown in agricultural soils, which are then consumed by the residents of the village of Cunha Baixa (Portugal),--located in an former uranium mining area. This study was conducted to address concerns expressed by the local farmers as well as to provide data for uranium-related health risk assessments for the area. Soils, irrigation water and edible tissues of lettuce, potato, green bean, carrot, cabbage, apple and maize (Latuca sativa L., Solanum tuberosum L., Phaseolus vulgaris L., Daucus carota L., Brassica oleracea L., Malus domestica Borkh, Zea mays L., respectively) were sampled and uranium determined. High uranium concentrations were found in some soils (U(total) > 50 mg/kg), in irrigation waters (218 to 1,035 μg/l) and in some vegetable foodstuffs (up to 234, 110, 30, 26, 22, 16 and 1.6 μg/kg fresh weight for lettuce, potato with peel, green bean pods, cabbage, corn, carrot and apple, respectively). However, the results of the toxicity hazard analysis were reassuring the estimated level of uranium exposure through the ingestion of these vegetable foodstuffs was low, suggesting no chemical health risk (hazard quotient <1) to this uranium exposure pathway for a local residents during their lifetime, even for the most sensitive part of the population (child).

Amperometric study of hydrogen peroxide biosensor with butadiene rubber as immobilization matrix

A carbon paste electrode bound by butadiene rubber has been newly constructed and its electrochemical properties have been investigated to test the practicability of the enzyme electrode. The binder of carbon powder was butadiene rubber dissolved in toluene and ground cabbage tissue was embedded in the matrix as an enzyme source. The electrode, which showed a mechanical robustness after volatilization of solvent, displayed good catalytic power (detection limit = 2.5 × 10 −5 M, S/N = 2) and electrochemically irreversible characteristics. Its symmetry factor and the exchange current density of the electrode used were 0.23 and 1.71 × 10 −3 A cm −2, respectively.

Growth of Listeria spp. in Shredded Cabbage Is Enhanced by a Mild Heat Treatment

Mild thermal processing can enhance the shelf life of cut fruits and vegetables by delaying the onset of spoilage and preserving the organoleptic properties of shredded cabbage. However, food safety issues related to this process have not been fully investigated. Therefore, the survival and growth of Listeria spp. on cabbage treated in this manner was examined. Experimentally, 24 strains of Listeria spp. (including L. monocytogenes) were inoculated onto cut and intact cabbage tissues and stored at 5 degrees C. All strains on intact tissues exhibited a moderate decline in numbers (up to 1.0 log CFU/cm(2)) over the 28-day storage period. Conversely, cut tissue supported growth of most strains during the first 7 to 14 days of incubation with maximum increases of 1.2 log CFU/cm(2). Subsequently, the survival or growth on heat-treated (50 degrees C for 3 min) and untreated shredded cabbage of four L. monocytogenes and four nonpathogenic Listeria spp. strains were compared during storage for 21 days at 5 degrees C. Growth on untreated shred for all strains was similar to the results observed on cut tissue with a maximum increase of approximately 1.0 log CFU/g. However, in the heat-treated cabbage shred all strains displayed a rapid increase in growth (up to 2.5 log CFU/g) during the first 7 days of incubation, which may be indicative of the destruction of an endogenous growth-inhibiting compound within the cabbage. In conclusion, this study shows that mild thermal treatments of cut cabbage may promote pathogen growth if other inimical barriers are not implemented downstream of the thermal treatment.

Determination of metaflumizone residues in cabbage and soil using ultra‐performance liquid chromatography/ESI‐MS/MS

A simple confirmatory method for the determination of metaflumizone in cabbage tissues and soil samples using ultra-performance liquid chromatography-ESI/MS/MS is presented. Metaflumizone residues in cabbage and soils were extracted with acetonitrile and an aliquot was cleaned up with primary and secondary amine. Two precursor product ion transitions for metaflumizone were measured and evaluated to provide the maximum degree of confidence in results. Under ESI negative conditions, quantitation was achieved by monitoring the fragment m/z = 302 and qualitative fragment m/z = 116.5 while also collecting their parent ion m/z = 505.5. Average recoveries for cabbage and soil at four different levels (0.01, 0.05, 1 and 5 mg/kg) ranged from 77.6 to 87.9% with RSD of 3.5-7.9% and RSD(R) of 4.5-7.1%. The coefficients of determination of R(2) > or = 0.9991 were achieved for metaflumizone calibration curves from 0.01 to 5.0 microg/mL. The metaflumizone LODs in cabbage and soil were determined to be both 0.001 mg/kg with a LOQ of 0.004 mg/kg. This method was able to demonstrate quantitative recoveries and provide confirmatory data for the identification of metaflumizone residues in cabbage tissues and the surrounding soils following commercial application.

배추무름병 원인균 분리 및 특성 연구

배추 무름병을 대상으로 식물병원균 감염모델을 확립하기 위하여 무름병변을 가진 배추조직으로부터 80개의 독립된 세균집락을 순수 분리하였다. 이들 균을 감염되지 않은 배추 잎의 주맥부위에 접종하여 24<TEX>${\sim}$</TEX>48 시간 만에 무름병변을 나타내는 8개의 균주를 1차 선별하였다. 다양한 미생물학적, 생화학적, 형태학적인 시험을 통하여 분석한 결과 서로 다른 특성을 나타내는 균이라고 여겨지는 3개의 균을 최종 선정하였고 이들은 모두 그람 음성균으로 판명되었고 RB1, RB2 및 RB6로 명명하였다. API 20E시험, VITEK 2 COMPACT 분석, 16S rRNA 염기서열 분석 등을 종합할 때 RBl 및 RB2는 Erwinia carotovorum subsp. odoriferum 아종으로, RB6는 Erwinia carotovorum subsp. carotovorum 아종으로 추정되었다. 이들 균들은 <TEX>$30^{\circ}C$</TEX>, 생리적 pH인 중성 pH에서 최적생육을 하였다. 이들은 배추의 상처 유무에 상관없이 초기 접종양과 비례하여 무름병을 유발하였으며, 상처가 없는 경우보다 상처가 있는 경우에 더욱 명확한 병변을 유발하였다. RBl의 경우 <TEX>$8.0{\times}10^8$</TEX> CFU/ml, RB2 균주는 <TEX>$10^9$</TEX> CFU/ml, RB6는<TEX>$4.7{\times}10^6$</TEX> CFU/ml에서 최초로 무름 증상을 나타냈다. 이들 균의 숙주 특이성을 관찰하기 위하여 14종의 야채에 접종한 결과 배추, 가지 파프리카에서만 무름병변을 유발하는 숙주 특이성을 나타내었다. 이 연구에서 사용된 실험재료들 및 감염모델은 향후 식물병원균의 감염기작해석에 크게 기여할 것으로 예상된다. In order to establish in vitro infection model for research of plant pathogen based on tissue softening disease in napa cabbage, eighty independent bacterial strains were isolated from the softened napa cabbage tissues. Eight bacterial isolates were primarily screened with the generation of reproducible tissue softening disease to fresh napa cabbages within 24<TEX>${\sim}$</TEX>48 hours after inoculation. Through various microbiological biochemical and morphological examinations, three Gram (-) isolates which harbor independent biological properties were finally chosen, and named as RBI, RB2 and RB6. Collective results obtained from API 20E test and analyses of VITEK 2 COMPACT and nucleotide sequences of 165 rRNA of each isolate proposed that isolates RBI and RB2 are close to the Erwinia carotovora subsp. odorifera, and RB6 is close to the Erwinia carotovora subsp. carotovora. These isolates grew optimally at <TEX>$30^{\circ}C$</TEX> with neutral pH culture condition. The isolates caused softening tissue disease with dose-dependent manner regardless of pre-surface damages of napa cabbage. Minimum dose to cause soft rot disease for RBI, RB2 or RB6 were <TEX>$8.0{\times}10^8$</TEX> CFU/mt <TEX>$10^9$</TEX> CFU/ml or <TEX>$4.7{\times}10^6$</TEX> CFU/ml respectively. These isolates caused tissue softening disease to eggplant, paprika and napa cabbage out of 14 different tested vegetables, indicating that these isolates damages specific plant tissues. The bacterial isolates obtained in this research and in vitro plant infection model will be adapted in the understanding of the mechanism of pathogenesis by plant pathogen.

Conventional crops and organic amendments for Pb, Cd and Zn treatment at a severely contaminated site

The ability of selected plants and amendments to treat Pb, Cd and Zn accumulations from a metalliferous waste disposal site was studied both in the greenhouse and field. Spinach ( Spinacea oleracea), cabbage ( Brassica oleracea), and a grass–legume mix (red fescue, Festuca rubra; ryegrass, Lolium perenne); and bean ( Vicia faba) were grown in the greenhouse on blast furnace slag or baghouse dust amended with composted peat (CP). All plant species accumulated Pb, Cd and Zn to varying degrees. Total soil metal concentrations had a marked influence on plant uptake. Topdressing versus incorporating CP had a significant ( p < 0.05) effect on spinach and cabbage tissue metal concentrations. Soil Pb and Zn tended to shift towards less bioavailable forms after treatment with CP. Field plots were treated with CP, farmyard manure (FYM), or inorganic fertilizer. Dry matter production of spinach, cabbage and a grass–legume mix was greatest on either the CP or FYM treatments. Phytostabilization in combination with organic amendments may be the most appropriate technology to ensure stabilization of soil metals at this site.

Genetic and Environmental Variation of Glucosinolate Content in Chinese Cabbage

Strong evidence exists to suggest that increased consumption of glucosinolates from Brassica vegetables is associated with reduced risk of cancer induction and development. Development of elite germplasm of these vegetables with enhanced levels of glucosinolates will putatively enhance health promotion among the consuming public. To evaluate levels of glucosinolate phenotypic variation in Chinese cabbage tissue and partition the total phenotypic variation into component sources (genotype, environment, and genotype-by-environment interaction), a set of 23 Brassica rapa L. var. pekinensis genotypes were grown in two different environments (field plots and greenhouse ground beds). Gluconasturtiin and glucobrassicin were found to account for ≈80% of total head glucosinolate content. Significant differences were found in glucosinolate concentrations between the lowest and highest genotypes for glucobrassicin (6-fold) and for gluconasturtiin (2.5-fold). Analysis of variance showed that for the three major glucosinolates (gluconasturtiin, glucobrassicin, and progoitrin), the genotypic effects described most of the phenotypic variation (62% averaged over the three compounds). The next most important factor was genotype × environment interaction (29%), whereas variation affiliated with the environment was found to be relatively minor (8%). These results suggest that genetic manipulation and selection can be conducted to increase glucosinolate content and the putative health promotion associated with consumption of Chinese cabbage.